Pump

ABSTRACT

The invention includes a diaphragm pump in which the space behind the diaphragm is evacuated to give the pump a maximum intake efficiency.

0111100 ttes a1emt Ray [4 Set. 1, 1972 PUMP 3,212,751 10/1965 l-lassa..25l/65 72 I t Z 1 f A Nmh 2,840,003 6/1958 Johnson etal ..92/942,785,638 3/1957 Moller ..251/65 [73] Assignee: International Telephoneand Tele- 2,669,249 2/ 1954 Wittmann ..251/65 graph Corporation, NewYork, NY. 2,655,306 10/1953 Nefi ..417/28 2,463,766 3/1949 Hadley..417/517 [22] 2,392,117 l/l946 Burks ..417/521 [21] App1.No.: 6,9752,063,728 12/1936 DeVille ..417/57l Related U.S. Application DataFOREIGN PATENTS OR APPLICATIONS [63] Continuation of Ser. No. 745,597,July 17, 647,481 7/1937 Germany 1968, abandoned.

Primary Examiner-Henry F. Raduazo [52] U.S. Ci 417/533, 417/ 5 71,92/48AttorneyC. Cornell Remsen, Jr., Walter J. Baum, [51] int. Cl ..F04b23/04, F04b 21/02, F0lb 19/00 Paul W. Hemminger, Charles L. Johnson andThomas [58] Field at Search ..103/148, 150, 227, 38; E. Kristofferson[57] S 2:r CT [56] References Clted The invention includes a diaphragmpump in which UNITED STATES PATENTS the space behind the diaphragm isevacuated to give the pump a maximum intake efiiciency. 3,250,225 5/1966Taplm ..417/413 3,227,093 1/1966 Taplin ..92/80 11 Cl, 3 Drawing FiguresPATENTED 3.692.437

sum 1 0F 3 INVENTOR. M/A 64 V PATENTEUSEP 19 '97? 3 692 .437

sum 2 OF 3 42 1,57 i fxzz INVENTOR.

PUMP

BACKGROUND OF THE INVENTION This invention relates to fluid handlingapparatus and, more particularly, to a pump or compressor.

There is a need for an efficient pump which can deliver clean, pure airuncontaminated by lubricants. In

the past, pumps using lubricants have been found unsatisfactory.

SUMMARY OF THE INVENTION In accordance with the present invention, adiaphragm pump is provided which can overcome the above-described andother disadvantages of the prior art. This pump comprises a housing anda back-up plate operated diaphragm which divides the housing into innerand outer chambers. The inner chamber is evacuated. Thus, the diaphragmis always stressed in the same direction against the moving back-upplate. Therefore, the diaphragm has a long, useful life. The vacuum alsomakes the pump unusually efficient in that the diaphragm is fullydistended by the vacuum on the intake stroke.

It is also a feature of the invention that a diaphragm back-up plate isemployed which has a curvature to conform to that of the diaphragm andthe housing internal surface. Therefore, fluid is exhausted with maximumefficiency.

Still another feature of the invention resides in the use of a magnet onthe back-up plate or on an intake valve, or on both. The magnet opensthe intake valve as soon as the pump is at the bottom of its stroke.This then makes the intake more efficient.

In accordance with the device of the present invention, theabove-described and other advantages of the invention will be betterunderstood when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, which are to beregarded as merely illustrative:

FIG. 1 is a vertical sectional view of a pump constructed in accordancewith the present invention;

FIG. 2 is a sectional view of the pump taken on the line 2-2 shown inFIG. 1; and

FIG. 3 is a sectional view of the pump taken on the line 33 shown inFIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, in FIG. I, thepump of the present invention is indicated at 10, including a housinghaving three parts 11, 12, and 13. These parts are bolted together bybolts, not shown. Diaphragms l4 and I5 are sealed in between housingsections 11, 12, and 13. Back-up plates 16 and 17 are provided fordiaphragms 14 and 15, respectively. Diaphragms 14 and 15 may float, ifdesired, on back-up plates 16 and 17. Back-up plates 16 and 17 arereciprocated back and forth by an eccentric 18 that is driven by apulley 19. Pulley 19 may be driven by an electric motor 40 shown in FIG.3 through a belt drive 41, if desired.

Housing sections 11 and 12 hold diaphragm 14 in place so that diaphragml4 divides a space or outer chamber 20 from an inner chamber 21.Diaphragm l5 similarly leaves an outer chamber 22. Chamber 20 has anintake valve 23 and an exhaust valve 24. Similarly, chamber 22 has anintake valve 25 and an exhaust valve 26. Intake valves 23 and 25 arerespectively spring-biased closed by leaf springs 27 and 28. Air filtersare provided for the intake at 29 and 30. The outlet of the pump isindicated at a threaded bore 31. Intakes to the pumpare provided atports 32 and 33 located inside air fllters 29 and 30.

The entire pump is preferably constructed of nonmagnetic materials withthe exception of a body 34 carried by intake valve 25, a permanentmagnet 36 carried by back-up plate 16, and a permanent magnet 37 carriedby back-up plate 17. Magnets 34 and 36 are oriented to attract eachother. The same is true of magnets 35 and 37.

It is an outstanding feature of the invention that inner chamber 21 isevacuated. A permanent vacuum may be created or an auxiliary pump may beprovided to maintain the vacuum as will be described.

In the operation of the pump 10, eccentric l8 reciprocates back-upplates 16 and 17 so that air is pumped alternatively from exhaust valves24 and 26. The vacuum in inner chamber 2]. always stresses diaphragms I4and 15 in the same inwardly direction. This vacuum keeps diaphragms 14and 15 tight against back-up plates 16 and 17. When magnet 37 is in theposition shown, it overcomes the force of spring 28 and the pressurewithin the chamber 22 and opens valve 25. The same is true when backupplate 16 is in its leftmost position.

It is an advantage of the invention that the vacuum in chamber 21 alwaysstresses diaphragms l4 and 15 in the same direction. Therefore, thediaphragms have a long, useful life. The pump is unusually efficientbecause the vacuum in chamber 21 distends the diaphragms on the intakestroke to obtain maximum draft on the air coming in through the intakevalves. Therefore, this makes the pump unusually efficient.

It is also a feature of the invention that the back-up plates have acurvature to match the curvature of the housing. For example, back-upplate 16 has a curvature at 38 to match the curvature 39 of housingsection 11. This again makes for maximum pump efficiency. The portion ofthe outer chambers 20 and 22 which surrounds intake valves 23 and 25 ismade as small as possible. Therefore, air is exhausted with maximumefficiency.

It is also a feature of the invention that magnets 36 and 37 open intakevalves 23 and 25 at the bottom of the pump stroke. Withdrawal of airthrough intake ports 32 and 33 is, therefore, made possible against theforces of leaf springs 27 and 28.

As stated previously, the vacuum in chamber 21 may be a permanentvacuum. On the other hand, it may also be produced by a pump. Such apump is indicated at 42 in the drawings. Eccentric 18 operates pump 42at the same time that plates 16 and 17 are reciprocated.

Pump 42 has a cylinder 43 which transverse holes 44 through whicheccentric 18 extends. A piston 45 is reciprocated in cylinder 43. Asshown in FIG. 3, cylinder 43 has longitudinal slots 46 and 47 throughwhich air enters pump 42. Air is exhausted by pump 42 through aconventional check valve 48. Air is then pumped out through a loose seal49 via a tube 50. Any oil in chamber 21 is driven back thereinto througha resilient seal 51.

What is claimed is:

l. A pump comprising: a pump body having a pumping chamber; an outletcheck valve mounted in said body to allow the escape of fluid. forcedout of said pump and to prevent the flow thereof backwards therethroughinto said pumping chamber; an inlet check valve to allow flow of fluidinto said pumping chamber and to prevent flow of fluid therethrough frominside of said pumping chamber to a point outside thereof, said bodyincluding a wall for said pumping chamber; a flexible diaphragm fixed insaid body to define said pumping chamber therewith, said pumping chamberbeing variable in size, said diaphragm being movable toward and awayfrom said wall, said pumping chamber being fluid tight except when oneof said valves is open, said body defining a fluid-tight vacuum chamberon the side of said diaphragm opposite the side thereof on which saidwall is located; first means fixed to said body inside said vacuumchamber for moving said diaphragm toward said wall; and a vacuum pumpfixed to said body, said vacuum pump being connected to pump fluid frominside said vacuum chamber to a point outside thereof, said vacuum pumpbein positioned inside said vacuum chamber. I

2. The invention as defined in claim 1, wherein second means areprovided which connect said first means and said vacuum pump, acylindrical drive shaft extending through said body from a pointexterior thereof to a point inside said vacuum chamber, third meansconnected to said shaft for driving said first means and said vacuumpump synchronously via said second means, an annular fluid-tight sealfixed in compression between said drive shaft and said body in aposition around said drive shaft to minimize fluid leakage into saidvacuum chamber around said drive shaft.

3. The invention as defined in claim 2, wherein said body has a secondwall, a second diaphragm fixed in said body, said second wall and saidsecond diaphragm defining a second pumping chamber said vacuum chamberbeing defined by said body and both of said diaphragms, and inlet andoutlet check valves for said second pumping chamber.

4. The invention as defined in claim 3, wherein said pumping chambershave a predetermined maximum cross section, said diaphragms having amaximum cross section in a plane perpendicular to said walls onlyslightly greater than said pumping chamber cross section.

5. The invention as defined in claim 1, wherein said body has a secondwall, a second diaphragm fixed in said body, said second wall and saidsecond diaphragm defining a second pumping chamber, said vacuum chamberbeing defined by said body and both of said diaphragms, and inlet andoutlet check valves for said second pumping chamber.

6. The invention as defined in claim 5, wherein said pumping chamber hasa predetermined maximum cross section, said diaphragm having a maximumcross section in a plane perpendicular to said wall only slightlygreater than said pumping chamber cross section.

7. The invention as defined in claim 1, wherein said pumping chamber hasa predetermined maximum cross section, said diaphragm having a maximumcross section in a plane perpendicular to said wall only slightlygreater than said pumping chamber cross section.

8. A pump comprising: a housing; flexible diaphragm means sealed in saidhousing dividing the space therein into inner and outer chamber means,said inner chamber means being evacuated, said diaphragm means includingtwo diaphragms dividing said housing into one inner chamber and twoouter chambers, said inner chamber means being said inner chamber, saidouter chamber means being said outer chambers; backup plate means forsaid diaphragm means, said back-up plate means being a back-up plate foreach diaphragm; intake and exhaust check valve means for said outerchamber means, said intake valve means being an intake valve in saidhousing extending into each outer chamber at the positions of eachcorresponding backup plate, said intake valve means also including aleaf spring to bias each intake valve closed, at least one magnet beingcarried by one of said back-up plate means and said intake valve means,and a ferromagnetic material being carried by the other to open saidintake valve means as soon as one corresponding backup plate ispositioned its minimum distance from the corresponding internal surfaceof said housing in a corresponding outer chamber, a corresponding intakevalve thereby being quickly opened at the bottom of the pump stroke toprovide for maximum intake eff ciency, said housing being made of anonmagnetic material; and power means to reciprocate said back-up platemeans to pump a fluid from said intake valve means to said exhaust valvemeans, the lower pressure in said inner chamber holding said diaphragmmeans back to cause said diaphragm means to withdraw fluid from saidintake valve means with improved efficiency, said power means includingmeans to reciprocate said back-up plates in unison in a manner to causethe intake valve to open in one outer chamber while the intake valve inthe other chamber is closed, and vice versa, so as to pump fluid out ofsaid outer chambers alternately, said diaphragm having a uniformthickness, said housing having a dish-shaped internal surface in each ofsaid outer chambers for each of said diaphragms to contact, saiddish-shaped surfaces being flat over a major central portion thereof andbeing concave toward said inner chamber of the periphery thereof, eachsaid back-up plate having a curvature to mate with each correspondingouter chamber surface.

9. The invention as defined in claim 8, wherein each of said intakevalves is adapted to be opened by a ferromagnetic material carriedthereby and carried by each corresponding back-up plate, the magnet ineach case having a sufficient force of attraction to open eachcorresponding intake valve against the pressure in said outer chambersand against the force of said springs when the corresponding back-upplate is at the bottom of the pump stroke.

6 10. The invention as defined in claim 9, wherein each attraction. ofsaid intake valves is adapted to be opened by a fer- 11. The inventionas defined in claim 10, wherein romagnetic material carried by eachcorresponding SaidPOWeI' incllldfes an auxiliary Vacuum P p b k plate, hSpring f each intake valve being to withdraw air from said inner chambermeans. sufficiently strong to overcome the magnetic force of 5

1. A pump comprising: a pump body having a pumping chamber; an outletcheck valve mounted in said body to allow the escape of fluid forced outof said pump and to prevent the flow thereof backwards therethrough intosaid pumping chamber; an inlet check valve to allow flow of fluid intosaid pumping chamber and to prEvent flow of fluid therethrough frominside of said pumping chamber to a point outside thereof, said bodyincluding a wall for said pumping chamber; a flexible diaphragm fixed insaid body to define said pumping chamber therewith, said pumping chamberbeing variable in size, said diaphragm being movable toward and awayfrom said wall, said pumping chamber being fluid tight except when oneof said valves is open, said body defining a fluid-tight vacuum chamberon the side of said diaphragm opposite the side thereof on which saidwall is located; first means fixed to said body inside said vacuumchamber for moving said diaphragm toward said wall; and a vacuum pumpfixed to said body, said vacuum pump being connected to pump fluid frominside said vacuum chamber to a point outside thereof, said vacuum pumpbeing positioned inside said vacuum chamber.
 2. The invention as definedin claim 1, wherein second means are provided which connect said firstmeans and said vacuum pump, a cylindrical drive shaft extending throughsaid body from a point exterior thereof to a point inside said vacuumchamber, third means connected to said shaft for driving said firstmeans and said vacuum pump synchronously via said second means, anannular fluid-tight seal fixed in compression between said drive shaftand said body in a position around said drive shaft to minimize fluidleakage into said vacuum chamber around said drive shaft.
 3. Theinvention as defined in claim 2, wherein said body has a second wall, asecond diaphragm fixed in said body, said second wall and said seconddiaphragm defining a second pumping chamber said vacuum chamber beingdefined by said body and both of said diaphragms, and inlet and outletcheck valves for said second pumping chamber.
 4. The invention asdefined in claim 3, wherein said pumping chambers have a predeterminedmaximum cross section, said diaphragms having a maximum cross section ina plane perpendicular to said walls only slightly greater than saidpumping chamber cross section.
 5. The invention as defined in claim 1,wherein said body has a second wall, a second diaphragm fixed in saidbody, said second wall and said second diaphragm defining a secondpumping chamber, said vacuum chamber being defined by said body and bothof said diaphragms, and inlet and outlet check valves for said secondpumping chamber.
 6. The invention as defined in claim 5, wherein saidpumping chamber has a predetermined maximum cross section, saiddiaphragm having a maximum cross section in a plane perpendicular tosaid wall only slightly greater than said pumping chamber cross section.7. The invention as defined in claim 1, wherein said pumping chamber hasa predetermined maximum cross section, said diaphragm having a maximumcross section in a plane perpendicular to said wall only slightlygreater than said pumping chamber cross section.
 8. A pump comprising: ahousing; flexible diaphragm means sealed in said housing dividing thespace therein into inner and outer chamber means, said inner chambermeans being evacuated, said diaphragm means including two diaphragmsdividing said housing into one inner chamber and two outer chambers,said inner chamber means being said inner chamber, said outer chambermeans being said outer chambers; back-up plate means for said diaphragmmeans, said back-up plate means being a back-up plate for eachdiaphragm; intake and exhaust check valve means for said outer chambermeans, said intake valve means being an intake valve in said housingextending into each outer chamber at the positions of each correspondingback-up plate, said intake valve means also including a leaf spring tobias each intake valve closed, at least one magnet being carried by oneof said back-up plate means and said intake valve means, and aferromagnetic material being carried by the other to open said intakevalve means as soon as one corresponding back-up plate is positioned itsminimum distance from the corresponding internal surface of said housingIn a corresponding outer chamber, a corresponding intake valve therebybeing quickly opened at the bottom of the pump stroke to provide formaximum intake efficiency, said housing being made of a nonmagneticmaterial; and power means to reciprocate said back-up plate means topump a fluid from said intake valve means to said exhaust valve means,the lower pressure in said inner chamber holding said diaphragm meansback to cause said diaphragm means to withdraw fluid from said intakevalve means with improved efficiency, said power means including meansto reciprocate said back-up plates in unison in a manner to cause theintake valve to open in one outer chamber while the intake valve in theother chamber is closed, and vice versa, so as to pump fluid out of saidouter chambers alternately, said diaphragm having a uniform thickness,said housing having a dish-shaped internal surface in each of said outerchambers for each of said diaphragms to contact, said dish-shapedsurfaces being flat over a major central portion thereof and beingconcave toward said inner chamber of the periphery thereof, each saidback-up plate having a curvature to mate with each corresponding outerchamber surface.
 9. The invention as defined in claim 8, wherein each ofsaid intake valves is adapted to be opened by a ferromagnetic materialcarried thereby and carried by each corresponding back-up plate, themagnet in each case having a sufficient force of attraction to open eachcorresponding intake valve against the pressure in said outer chambersand against the force of said springs when the corresponding back-upplate is at the bottom of the pump stroke.
 10. The invention as definedin claim 9, wherein each of said intake valves is adapted to be openedby a ferromagnetic material carried by each corresponding back-up plate,the spring for each intake valve being sufficiently strong to overcomethe magnetic force of attraction.
 11. The invention as defined in claim10, wherein said power means includes an auxiliary vacuum pump towithdraw air from said inner chamber means.